Xbase++

Bind and Listen on an Available Port in a Range

Demonstrates Socket.BindAndListenPortRange, which searches an inclusive port range for an available TCP port, binds it, and begins listening. It returns the selected port, or -1 on failure.

Background. This is useful when any of several ports is acceptable and the application needs to discover which one was bound.

Chilkat Xbase++ Downloads

Download Chilkat for Xbase++

Xbase++

LOCAL oSocket
LOCAL nBoundPort

oSocket := CreateObject("Chilkat.Socket")

//  Search the inclusive port range for an available TCP port, bind it, and begin listening.  The
//  method returns the selected port, or -1 when no port can be bound.
nBoundPort := oSocket:BindAndListenPortRange(5000, 5100, 25)
IF (nBoundPort < 0)
    ? oSocket:LastErrorText
    oSocket:destroy()
    RETURN
ENDIF

? "Listening on port " + Str(nBoundPort)

oSocket:destroy()